Safety device for vehicle brake systems



1953 H. H. OSBORNE SAFETY DEVICE FOR VEHICLE BRAKE SYSTEMS 2SHEETS-Sl-iEET 1 Filed April 10, 1.950

INVENTOR. 7 Hey/ y H. Osborne kMM/M ff'cl MM 5?! Filed April 10, .1950

Ja 6, 1953 H. OSBORNE 2,624,176

SAFETY DEVICE FOR VEHICLE BRAKE SYSTEMS 2 SHEETS-SHEET 2 nmnl lm IN VENTOR. Henry ll. Osborne Patented Jan. 6, 1953 UNITED STATES QFFICE ORVEHICLE BRAKE SAFETY DEVICE F STEMS Henry H. Osborne, Gresham,

Leo M. Jansen, Gresham,

reg., assignor to Greg.

3 Glaims.

The present invention comprises an improved safety device for insertionin a hydraulic brake system of the type including a master cylinder fromwhich conduits lead to individual braking mechanisms associated with thewheels of the vehicle, the safety device being of improved constructionwhereby mechanical failures heretofore encountered in such devices areto a large part eliminated. All such devices heretofore known to mecomprise some form of floating piston or related mechanism, many ofwhich have been known to fail to operate, with the result that thebrakes may not be set with the speed required in an emergency, or theloss of a large proportion of the fluid used in the brake system. Thepresent invention comprises a flexible diaphragm which cannot becomelodged or otherwise held against movement and which cannot permitexcessive loss of fluid from the system.

The objects and advantages ofthe present invention will be more readilyascertained from inspection of the following specification taken inconnection with the accompanying drawing wherein like numerals refer tolike. parts throughout, while the features of novelty will be moredistinctly pointed out in the appended claims.

In the drawing,

Fig. 1 is a schematic view of a preferred arrangement of hydraulic brakesystem employing the present invention;

Fig. 2 is a side elevation of one form of the present invention; I

Fig. 3 is a vertical section taken substantially along line 3-3 of Fig.2;

Fig. 4 is an end elevation of a modified form of the present invention;

Fig. 5 is anend elevationof a further cation of the present invention;

Fig. 6 is a vertical section taken substantially along line 6-45 of Fig.4;

Fig. 7 is a side view of a' further modification of the invention indual unit form;

Fig. 8 is a section taken substantially along line 8-8 of Fig. 7;

Fig. 9 is a side view of a single unit similar to the dual unit of Fig.7;-

Fig. 10 is a section taken substantially along .linelfl-lo of Fig. 9;and

Fig. 11 is a schematic view of a vehicle having the safety devices ofFigs. '7 and 9 thereon.

A hydraulic brake system on an automotive vehicle is schematicallyillustrated in Fig. wherein it. is seen that a master cylinder It isassociated with. an; operating plunger H pivotally-cennected to thebrakepedal l2, A conduit modifisystem including lines [3, l4, l5 andliiconnects lllto the input side of a plurality of safety devices I!formed in accordance with the present invention, which areinterposedbetween the -master cylinder and the braking mechanisms indicated at I8.Preferably there is one such safety device associated with each of therear wheels of the vehicle and a third safety device associated with thefront pair of wheels of the'vehicle in order that failure of theconduits leading from the safety devices to the wheels may not result inloss of fluid from the entire system, there being but a single safetydevice associated with the front pair of wheels in order that steeringcontrol may not be lost if one or the other front wheel brakingmechanism should lose its fluid.

One form of the present invention is illustrated in Figs. 2 and 3wherein it is seen that the safety device comprises a pressure chamberformed by a pair of flanged shells and 2| which are connected togetheralong their peripheries by a plurality of short studs 22. The shell 29is provided with an internally threaded, central nipple 23 forconnection with an inlet conduit leading from the master cylinder, andthe shell 2| is provided with a centrally disposed, threaded nipple 24for connection to the conduit leading to the associated brakingmechanism. The interior of the pressure chamber is divided into twoseparate compartments by a flexible disc diaphragm 25, the periphery ofwhich is clamped between the flanged portions of the shells and isprovided with a plurality of openings for the passage of studs 22. Thediaphragm is formed of suitable impervious, flexible material inert tothe braking fluid and may be provided with a peripheral fold 26 in orderthat flexing without rupturing may be accomplished.

Means are associated with the shells 28'- and 2i for providing a passageby-passing the diaphragm, such means comprising a pair of blocks 30 and3'! welded to the upper, outer surfaces of the shells. A by-pass passageincludingthe portions 32, 33 and 34 may lead fluid'from'on'e" side ofthe diaphragm to the other side; the passage normally being closed by apair of needle valves 35 and 35 threadedlyl mounted in the members" 30and 3! respectively, theinner ends thereof'be'- ing normally seated invalve seats Frl. andbB re spectively, formed in the by-pas'si passage:so that the two compartments of the pressurechamber are normallymaintained against communication with each other. It is to beappreciated that only one valve need be provided, but two valves" maythe master cylinder be provided as shown for additional safety. If onlyone valve is provided one of the two members and 36 would be an ordinarystud for closing the drilling hole.

The blocks 34! and 3! are provided with a second passage similar to theby-pass passage 32, 33, 34, constituting an air bleeding passage whichis provided with opposed vent openings 55. A pair of needle valves arearranged to seal the air bleeding passage similarly to valves 35 and 35.

When a leak or break occurs in the fluid system it is invariably locatednear the wheel so that a safety device as arranged in Fig. 1 willprevent loss of fluid from the entire system. Usually leakage is slow sothat the loss becomes obvious before a serious accident results, but ifit should be rapid entire braking control will not be lost because ofthe safety device. There is usually a reserve supply of oil in themaster cylinder l8, which may be sent into the system by pumping thefoot pedal several times. This will cause the diaphragm to be displaceduntil its movement is blocked, whereupon braking pressure may be appliedto the remaining operative wheels.

After the leak has been repaired the system may be refilled by openingthe by-pass and bleed valves and pumping the brake pedal slowly whilepouring fluid into the master cylinder. When oil runs from the ventopening on the near side, its associated bleeding valve may be closedand pumping. continued until oil runs from the vent opening on the farside. At this time the safety device is filled and both bleeding valvesmay be closed, but the by-pass must remain open. The usual vent valve inthe brake assembly should now be opened and the operation continueduntil all air is driven from the system, whereupon all valves should beclosed.

The flexible diaphragm is preferably provided with a centrally disposed,thickened portion ii? in which is imbedded a metal disc 41. In the eventof a break in a line leading from the safety device the diaphragm willlie against the sides of the device as shown in dash lines, and the disc4| will prevent the pressure from rupturing the diaphragm opposite theoutlet opening.

In Figs. 4 and 6 there is illustrated a modified form of the presentinvention in which the pressure chamber comprises an elongated,cupshaped shell which is preferably provided with apertured side wings5| suitable for mounting the safety device on the chassis of thevehicle, and a flanged nut 52 threadedly engaged in the threaded, openend of the cup. The interior of the pressure chamber is divided intoseparate compartments by a resilient, cup-shaped diaphragm 53 providedwith a flange 54 at its mouth, the flange expanding outwardly from thecup so as to provide means for anchoring the cup in a suitably formed,annular recess 55 spaced slightly inwardly from the threaded mouth ofthe member 50. The flange is clamped in the recess 55 by a suitablyformed ring 56 which is engaged by the inner end of the closure nut 52.The nut 52 is provided with a threaded, central aperture 5? by means ofwhich an inlet conduit may be connected to the pressure chamber, and thebottom of the member 50 is provided with a threaded outlet opening 58.The cup-shaped diaphragm 53 tapers toward its base so as to divide thesubstantially cylindrical interior of the member 55 into two separatecompartments which are normally maintained against communication witheach other by the diaphragm.

The exterior of the threaded portion of the nut 52 is provided with anannular recess 60 with Which communicates a plurality of radiallyextending apertures Bl in order that communica- "tion may be establishedwith a portion 52 of a by-pass passage extending through a longitudinalflange 63 on the top of the member 55. A threaded needle valve 54 isthreadedly retained in the member 50, the inner end thereof beingtapered to seat in a valve seat 65 formed in the upper end of passage62. A longitudinally extending bore 66 drilled through the flange 53 andsealed by a screw 61 connects passage 52 with a second radial passage 68adjacent the bottom of the member 55, the passage 68 having a valve seat69 for reception of the tapered lower end of a second needle valve l5threadedly mounted in the flange 63. Lock nuts H and T2 are preferablyprovided to retain the needle valves in closed position.

In order that expansion of the cup-shaped diaphragm 53 shall take placesolely within the confines of the side walls thereof, the bottom of thediaphragm preferably rests against a disc 15 seated in the bottom of themember 55, the disc having a plurality of perforations H5 in its forwardsurface communicating with a passage i? leading through the interior ofthe disc and connecting with an annular groove it which communicateswith the passage 58. The passage ll also communicates with a pluralityof rearwardly extending perforations which lead to the concave innersurface of the disc so as to provide an open space communicating withthe outlet pas sage 58. The perforations and passages through the disc15 provide means for permitting the application of pressure to thebraking mechanism upon expansion of the sidewalls of the cupshapedmember 53, and also permit communication from one side to the other sideof the diaphragm when the needle valves are open.

The bottom wall 8| of the diaphragm is preferably substantially thickerthan the side wall and the thickening thereof preferably extendsupwardly into the side walls for a short distance so as to provide extrastrength at the points where extreme flexing might occur. However, mostof the expansion of the side wall of the diaphragm Will occur well uptoward the flange 54 during normal operation of the braking system.

It is contemplated that the units illustrated in Fig. 4 may be suppliedsingly or that the rear wheels may be served by a dual unit asillustrated in Fig. 5 wherein a pair of cup-shaped members identicalwith the single. cup-shaped member illustrated in Figs. 4 and 6 areclosed by a pair of nuts 52, the dual unit having lateral wings 5! formounting purposes and being connected by a web 9B. The elongated,relatively cylindrical form of pressure chamber illustrated in Figs. 4and 6 adapts itself more readily to association with the vehicle thanthe large disc forms illustrated in Figs. 2 and 3, in some types ofvehicles, and vice versa. r

In this form of safety device no vents are necessary since the outlet 58is at the top of the chamber and all air will be driven from the outletand may be bled out at the brake mechanism. Simi-: larly, any air whichmay have entered the inlet side will be removed through the passage 82located at the top of the chamber.

Figs. 7 and 8 illustrate a modified form of dia phragm safety device forinsertion in the line leading to the rear wheels of the vehicle. In thisform a pair of substantially identical shells I55 and HM are mounted atthe opposed sides of a acaarrez central, ann-ularfniember I 02, the samebeing retained iii assembled relation by a; plurality of studs I03 Theinterior of the space so provided is divide'd into"three 'compartmentsby: a pair of identical flexible diaphragmsi I'M'made of resilientmaterial such as a rubber substitute; The diaphragms are preferablyprovided with peripheral beads'indicated at I which are clamped inannular grooves in the opposed faces of the members I00, III'I andIIl'Zsov as to be anchored against displacement when pressure is applied tothe interior of the device. Preferably gaskets I66 are positionedbetween the members beyond the outer edges of the diaphragms. Thecentral member I02 is provided with an inlet opening I01 and each ofthemembers IIlIl'and IIII is provided with an outlet opening I08 andH39, respectively, leadingtothe individual brake. mechanisms. Thecentral portion of each of the diaphragms' is thickened as indicated-atI I0 and a metallic disc II I is imbedded-in the thickened portion toprevent rupturing of the diaphragm if it should be displaced and pressedagainst the interior surface ofthe safety device.

Each of the members I80, IBI and IE2 is provided with an upwardlyextending passage leading from the extreme top portion of the interiorspace and terminating in an upwardly facing valve seat with whichcooperates a needle valve H2, H3 and H4, respectively, and each of thedrill holes in which the needle valves are seated is connected to itsneighbor through a laterally extending opening forming a portion of aby-pass passage as previously described with respect to Figs. 2 and 3.Alongside of the by-pass valves there are located a pair of air bleedingvalves I I5, one of which communicates with the top of the compartmentdefined by the member I00 and the diaphragm adjacent thereto through anopening H6, and one of which communicates with the compartment definedby the member IGI and the diaphragm adjacent thereto through acorresponding opening so that each of the exterior compartments may bevented to the atmosphere through an air bleeding passage extendingthrough the side of member I00 as indicated at I II. In order to becertain that the diagram will return to the position illustrated in Fig.8, a wire spring I20 is mounted between the diaphragm and the adjacentouter member, the spring being in the form of a spiral helix with itssmaller end resting against the thickened portion IIU of the diaphragmand its larger end resting against the outer member, the free endthereof being anchored in one of the openings leading to one of thevalves.

When this form of the invention is mounted on a vehicle as shown in Fig.11, the opening I0! is connected to a tube I2I leading from the mastercylinder I22, the opening N18 is connected to a tube I23 leading to oneof the rear wheels, and the opening I09 is connected to a tube I24leading to the other rear wheel. Flexible inserts in the tubes areindicated at I25, and it is at one of these inserts that leakage in thesystem usually occurs. If a leak should occur the outlet compartmentwould be drained because of the pressure intermittently applied to theinterior com partment. However, as soon as the diaphragm became seatedagainst the interior wall of the safety device and the foot pedaloperated once or twice to refill the system from the reserve supply ofthe master cylinder, pressure could be applied to the other brakingmechanism. After the break is repaired refilling and venting of thesysterm. would be: accomplished. as previously; de:--.

scribed...

Eigsa- 9'5 and Y10 illustratera single ':unit-. formed as describedwithirespect to: the dual unit of Figs. '7 and-8;. In this formatpairof'members; I30. and I'3'2I: arerjcined together by studsi I32 anddivided intoian; inlet. compartment and an outlet compartment bydiaphragm I33 as. previously. described. The diaphragm' is provided withathickened, central portion I-34 to prevent rupturing;,.which portion isreinforced'by a metal disc" I352. By-pass valves I36 are: provided: as.previously' described, and at least one. vent valve I3! is provided; thesame; controlling. an air bleed.- ing outlet: I38. A spring.- I39 is.preferably provided to. insure return of the: diaphragm toitscentral"position. Thar-member" I30, is: provided with an. inlet. opening: I40tube-1 I 417 leading to. the

which. is" connected. to: the: tube I43: from whichabranche's leadto:the front wheel braking, mechaniSmsiandLin" which a flexible insert his;provided. The operations: of filling and'ventin'g Y o'f this fornr are'iexactly as: previously described.

Having illustrated and described preferred embodiments of my invention,it should be apparent to those skilled in the art that the inventionpermits of modification in arrangement and detail. I claim as myinvention all such modifications as come within the true spirit andscope of the appended claims.

I claim:

1. A safety device for insertion in a hydraulic brake system of the typeincluding a master cylinder from which conduits lead to individualbraking mechanisms associated with the wheels of a vehicle, comprising apressure chamber having an inlet for communication with the mastercylinder and an outlet for communication with one of the brakingmechanisms, a flexible diaphragm dividing said pressure chamber into twoseparate compartments which are normally maintained againstcommunication with each other, means providing a passage by-passing saiddiaphragm for interconnecting said compartments, said passage beingformed to provide a pair of valve seats, a pair of needle valvescooperatively associated with said valve seats whereby communicationbetween said compartments may be established, said pressure chambercomprising a cup-shaped shell having a threaded open end and a threadedclosure member mounted in said open end, said diaphragm comprising acupshaped, resilient member having an external flange at its open end,said shell having an internal, annular seat adapted to receive saidflange, a washer interposed between said flange and said closure memberto clamp said flange against said seat, and a perforated disc interposedbetween the bottom of said shell and the bottom of said resilientmember, said outlet being in the bottom of said shell.

2. A safety device for insertion in a hydraulic brake system of the typeincluding a master cylinder from which conduits lead to individualbraking mechanisms associated with the wheels of a vehicle, comprising apressure chamber having an inlet for communication with the mastercylinder and an outlet for communication with one of the brakingmechanisms, a flexible diaphragm dividing said pressure chamber into twoseparate compartments which are normally maintained againstcommunication with each other, means providing a passage Icy-passingsaid which is connected to: master cylinder, and the member: I3I isprovided with. an'outlet. opening;

diaphragm for. interconnecting said compartments, valve means normallyclosing said bypass passage, and a perforated member inserted in saidpressure chamber between said flexible diaphragm and "said outlet, saidperforated member permitting free passage of hydraulic fluid from saidchamber but protecting said flexible diaphragm from being forced intothe outlet from said chamber.

3. A safety device for insertion in a hydraulic brake system of the typeincluding a master cylinder from which conduits lead to individualbraking mechanisms associated with the Wheels of a vehicle, comprising apressure chamber having an inlet for communication with the mastercylinder and an outlet for communication with one of the brakingmechanisms, a flexible diaphragm dividing said pressure chamber into twoseparate compartments which are normally maintained againstcommunication with each other, means providing a passage by-passing saiddiaphragm for interconnecting said compartments, valve means normallyclosing said bypass passage, and a perforated member inserted in saidpressure chamber between said flexible 8,. diaphragm and said outlet,said perforated member permitting free passage of hydraulic'fiuid fromsaid chamber but protecting said flexible diaphragm from being forcedinto the outlet from said chamber, said perforated memberrcomprisingmeans spacing the surface thereof from the surface of said chamberwhereby fluid may flow freely through said outlet upon being forced fromsaid chamber.

HENRY H. OSBORNE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Great Britain May 5, 1930

